Borderline Personality Disorder Misdiagnosis

BPD is a complex condition with several features that differ from person to person and at different times in the life span. It is also an intense and extreme way of living, so co-morbid (co-occurring) conditions are common, such as depression, substance misuse, ec.

Diagnosing and treating BPD is difficult because patients will often receive a diagnosis for the observable symptoms (mood management or addiction treatment) rather than address the underlying causes and roots of these issues. In these situations, treatment is less likely to be successful, as it addresses symptoms rather than the cause.

Compared to those diagnosed with other personality disorders, people with BPD showed a higher rate of also meeting criteria for:


  • mood disorders, including major depression and bipolar disorder
  • anxiety disorders, including panic disorder, social anxiety disorder, and post-traumatic stress disorder (PTSD)
  • other personality disorders
  • substance abuse
  • eating disorders, including anorexia nervosa and bulimia
  • attention deficit hyperactivity disorder
  • somatoform disorders
  • dissociative disorders


Common Misdiagnosis

The following are common misdiagnoses and overlapping conditions:

Mood Disorders, including Bipolar Disorder and Major Depressive Disorder

Having BPD feels terrible and can lead to a depressing life, so it is common and understandable to experience depressive times and, even, to get clinical depression. However, in general the low mood experienced within BPD feels different and has a different profile, despite having similar biological processes.

In BPD, “moods” shift rapidly from one state to another, depressed to angry to highly anxious to despondent to excitable to frustrated to vengeful to scared. These are different emotional and intellectual states of mind, while mood disorders are more linear shifting much more slowly between depressed and elated. BPD shifts are more responsive to situations, particularly interpersonal and perceived rejection. The thinking processes aligned to BPD are very different from mood disorders, so thoughts and feelings normally associated with depression or anxiety are the same, but the causes for these are different.

Some psychiatrists consider Borderline Personality Disorder to be a mood disorder on a hypothesised bipolar spectrum. This makes sense because there is a large mood component to BPD and the only evidenced medical treatment is mood stabilisers, and less often antipsychotics; the treatment for Bipolar. So there is a great deal of overlap of symptoms and treatment from a psychiatric point of view. Many physicians choose the Bipolar Mood Disorder label to save the patient the stigma of a BPD diagnosis and because it makes little difference if there is no difference in treatment. Howver, while there are grounds for confusing the two disorders, especially on initial presentation, they are significantly different for the person living with the condition, have a different course and from a psychological perspective treatment is dramatically different.

The core of this discussion is that Borderline and Mood symptoms are different, but similar enough on a snapshot to get them confused. It needs a thorough, experienced professional assessment to get a clear and comprehensive picture of their interactions.

Anxiety Disorders, including panic disorder, social anxiety disorder

Like mood symptoms, anxiety is a common, if not daily, feature that makes living with BPD stressful and compromises the ability to function. This is due to the easily aroused nervous system which has likely undermined the process of learning to develop coping skills. While this makes developing a full anxiety disorder more likely, the BPD anxiety profile is itself different with a different balance of symptoms.

Post-Traumatic Stress Disorder (PTSD)

High arousal (e.g. stress, anxiety, anger, fear, etc) leads to poor memory, understanding, learning and rationalising. In BPD a person lives most of their life in a heightened state so they have long-term poor engagement with social learning, the ability to grow and learn life lessons and skills from those around you. This leads to a weak sense of self and poor auto-biographical memory, the memory of your past and how this has created your character and understanding of the environment around you.

Trauma is an unfortunate likelihood of living in the modern world, but for people with BPD it can have a greater impact on their daily lives. This has several causes:

Firstly, they are more sensitive to understanding an event as a trauma as their nervous system responds so extremely. In addition, the coping skills and auto-biographical memory that protects others by being able to contextualise events in ways that make them feel safe and secure is under-developed. Finally, BPD erratic and reckless behaviours make them more likely to get into situations that are unsafe and could be traumatic.

Therefore, it is common for people with BPD to be traumatised in a way that strongly resembles PTSD. However, there are fundamental differences in the types of events, the effect on their lives and the treatment is significantly different.

Other Personality Disorders

All personality disorders have some key features in common and there are many that have overlapping features. Differentiating one from another can be difficult and there can also be features from several. So it is common for the balance of symptoms to shift through life stages and with changes in circumstance. Equally, it is possible for diagnosis to shift as the person shifts with one personality profile becoming more dominant or the professional gathering more information.

For example, men with BPD (a rarer diagnosis) may be treated for anti-social personalty disorder as their presenting trait is getting into trouble with the law. This assumes the cause of such behaviour is lack of care for others and consequences, rather than BPD symptoms such as risky or impulsive behaviour.

Substance Abuse

Due to the erratic and reckless behavioural pattern, difficulty managing mood/anxiety, poor sense of self and extreme social attachments, misuse of substances is common. This is often the reason that most people with BPD, as well as most other forms of personality disorder, come in contact with professional services. Once again, the usage pattern, psychological needs being fulfilled and treatment are very different from a person with a primary substance abuse problem.

Other Co-morbid (Co-Occuring) Disorders

Likewise, there are a number of other areas where the symptoms of BPD directly create or mimic distinct psychiatric disorders. Most commonly are Eating Disorders, including Anorexia Nervosa and Bulimia, Attention Deficit Hyperactivity Disorder (ADHD), Somatoform Disorders (mimicking physical symptoms) and Dissociative Disorders.

Our Borderline Personality Disorder Portal

The following pages are designed to provide additional information and advice on BPD treatment and our approach: